Impact of gestational age on neonatal hearing screening in vaginally-born late-preterm and early-term infants.

BACKGROUND: Late-preterm and early-term (LP-ET) infants, defined herein as 35(0)-37(6) weeks' gestation, often fail on 1st otoacoustic emissions (OAE) test. HYPOTHESIS: LP-ET infants fail more than term infants (38(0)-42 weeks' gestation) on the 1st OAE test. Aim : To evaluate the effect of gestational age on the 1st OAE test. METHODS: We studied 1,572 vaginally-delivered (VD) infants ≥35 weeks' gestation (1.1.2011-30.9.2011). Perinatal and neonatal variables and results of OAE tests were recorded. RESULTS: LP-ET infants, compared to full-term infants, had a significantly 2-fold higher need for repeated hearing tests: 80.2 versus 43.3 tests/1,000 neonates, respectively (p = 0.026). Univariate analysis showed that late prematurity and age at 1st OAE were significantly associated with failure on 1st OAE. At age 24-42 h, failure on 1st OAE was 2-fold higher in the LP-ET infants than in full-term infants: 9.4 versus 4.7% (p = 0.02). Risk for failure on 1st OAE was age-dependent: 9-fold higher when 1st OAE was performed at 24-42 h of age (5.3%) versus 0.6% after age 42 h. Multivariate analysis showed that variables that were independently significantly associated with failure on 1st OAE included late prematurity (OR 2.0 (1.1-3.7)) and age at 1st OAE (OR 9.2 (1.2-70.7)). CONCLUSIONS: Compared to term infants, VD LP-ET infants had 2-fold higher rates of failure on 1st OAE (up to 42 h of life) and needed repeated hearing tests. Failure rates after 42 h become negligible in both groups. In VD LP-ET infants, 1st OAE is better performed after 42 h of age.

Delayed first otoacoustic emissions test decreases failure on neonatal hearing screening after caesarean delivery.

AIM: Caesarean delivery (CD) was associated with a 3.2-fold higher failure on 1st otoacoustic emissions (OAE) hearing test. We aimed to verify whether postponing 1st OAE beyond 48 h in CD infants decreases hearing screening failure. METHODS: We compared two groups of CD infants as to failure on 1st OAE test: early-1st OAE (n = 560): 1st OAE at 12- to 48-h-olds and late-1st OAE (n = 566): 1st OAE at 48- to 132-h-olds. RESULTS: Compared with early-1st OAE group, the failure rate among late-1st OAE infants was significantly sixfold lower (20.5% vs. 3.4%), with sixfold lower need for repeated tests: 205 vs. 34 tests/1000 CD neonates (p < 0.001). The failure rate decreased with increasing age in both groups (p < 0.001). Univariate analysis: timing of 1st OAE (late vs. early) was significantly associated with failure on 1st OAE. Multivariable analysis: late (48-132 h) 1st OAE test was associated with a 7.7-fold lower risk for failure of 1st OAE, OR (95% CI): 0.13 (0.08-0.21). CONCLUSION: Among CD infants, the risk for failure in late-1st OAE group (>48 h) was 7.7-fold lower, with a sixfold lower need for repeated hearing tests. Delaying 1st OAE in CD infants beyond 48 h of age (preferably between 48 and 132 h) decreases neonatal OAE screening failure.

Birth by cesarean delivery and failure on first otoacoustic emissions hearing test.

BACKGROUND: Neonatal hearing screening occasionally fails. We noticed that infants born by cesarean delivery (CD) appeared to fail the first otoacoustic emissions (OAE) test more frequently than infants delivered vaginally (VD). This might increase maternal anxiety. We aimed to evaluate the influence of mode of delivery on failure to pass the first OAE. METHODS: Overall, 1653 infants of >35 weeks' gestation were evaluated. OAE was performed before discharge. Perinatal-neonatal variables and results of OAE were recorded retrospectively. RESULTS: Compared with VD infants, CD infants had lower gestational age and 1-minute Apgar, more small for gestational age (SGA), and earlier age at first OAE. Univariate analysis: CD, male gender, gestational age 35 to 37 weeks, birth weight ≤ 2500 g, SGA, and younger age at first OAE were significantly associated with failed first OAE. In infants weighing 2501 to 4000 g, CD infants had 3-fold higher rates of failed first OAE in comparison with VD infants (20.7% vs 7.1%) before 48 hours of age. In the multivariate analysis, variables independently significantly associated with failed first OAE were male gender (odds ratio [OR] 1.42 [1.02-1.98]), CD (emergency CD: OR 3.18 [2.21-4.57], elective CD: OR 3.32 [2.04-5.42]), age 12 to 23 hours at first OAE (OR 3.1 [2.1-4.58]) and SGA (OR 2.2 [1.15-4.28]). CONCLUSIONS: CD infants had significantly higher failure rates on first OAE. We speculate that CD is accompanied by retained fluid in middle ear which may impair neonatal hearing. The timing of first OAE after CD should preferably be postponed beyond 48 hours of age to improve OAE passage and minimize maternal anxiety and costs.